So when i got off of work today I was informed by my roommate that two of my betta girls had suddenly developed a fungus, and that she had pulled them out of the tank and QTd them for me. I immediately whipped some AQ salt water, but one, my beloved pineapple girl Toxic, had already passed. The other, Fleur, is not doing well at all. My other four girls (Big Mama, Aurora, Stormcloud, and my unnamed wildcolor) have not developed symptoms, nor have any of my other fish. I very recently lost my crowntail girl Princess and one of my new cory cats, but no fungus was present. They just... died. No clue why.

Housing
What size is your tank? 20 gallons
What temperature is your tank? 81 F
Does your tank have a filter? Two
Does your tank have an air stone or other type of aeration? Yes
Is your tank heated? Yes
What tank mates does your betta fish live with? 9 neon tetras, 6 platies, four cory cats, one marble hatchetfish, and one apple snail (hence the two filters)

Food
What type of food do you feed your betta fish? TetraMin tropical flakes, NutriFin Max, frozen bloodworms, frozen brine shrimp, freeze dried tubifex worms as an occasional treat
How often do you feed your betta fish? twice a day, fast on Sunday
Maintenance
How often do you perform a water change? twice weekly
What percentage of the water do you change when you perform a water change? 50%
What type of additives do you add to the water when you perform a water change? FloraPride, AquaSafe

Water Parameters:
Have you tested your water? If so, what are the following parameters? Yes, just today actually

Symptoms and Treatment
How has your betta fish's appearance changed? White film covering the eyes, fuzzy white substance on the head of Toxic's body
How has your betta fish's behavior changed? She's currently in very shallow water floating head down
When did you start noticing the symptoms? My roommate noticed while I was at work this evening, so sometime after 3pm
Have you started treating your fish? If so, how? Fleur is being acclimated to AQ salt water at 3tsp/gallon, have not started treating the main tank due to lack of open fish stores
Does your fish have any history of being ill? Fluer had SBD when I purchased her, which I corrected. Toxic has never been ill
How old is your fish (approximately)? They're pet store fish, so I don't know

Should I go to the store tomorrow and buy meds to treat my whole tank? Should I QT all four healthy girls in AQ salt water? With Fleur floating head down, is she definitely gone for, or is there anything I can do? Please help, my sororty has gone soooo well, and I love my girls, and all my fish, and I don't want to lose them :(

Sounds like columnaris or saprolegnia. Without knowing which one it is exactly, your best bet would be to treat with aquarium salt so good job getting her into the 3 tsps right away. That's what I was going to recommend. Lower the heat to 76 degrees in case it is columnaris.

QTing all of your girls is totally up to you. If you're very busy with school, it might not be the best idea because of the very frequent water changes required.

With these diseases, it's very difficult to make a correct diagnosis without doing a skin scraping and viewing it under the microscope. Because columnaris is a bacterial disease and saprolegnia is a fungal disease, they would require different types of medications to treat them so at the moment, I'm reluctant to suggest any medications. It might help if you can give me a quick rundown on your tank. When did Princess and your cory die and what kind of symptoms did they have?

Well, I'm not busy, and Big Mama just started acting funny and developing some fuzz, so I QTd her, and now that there are only three girls in the tank... Might just be best to seperate and preventatively treat them. Especially since Fleur passed overnight :( Princess and my cory cat died Wednesday. Princess had absolutely no symptoms at all. She just... died. I examined her body for fungus or other external symptoms, and there was absolutely nothing. The cory cat, on the other hand, I think just didn't adapt well to my tank. My PH was low when I got him and his buddy, and both started acting funny when I put them in the tank. Raised my PH gradually and now the surviving one is behaving normally and interacting with my other three cory cats.

I'm so sorry Fleur passed. I agree with you, QT them all. Since this is moving pretty fast, I'm going to go ahead and say it's acute columnaris. I don't think saprolegnia moves this quickly.

For a conservative treatment, you can keep all affected girls in 3 tsps of aquarium salt per gallon and lower the heat to 76 degrees for 10-14 days. For an aggressive treatment, you can treat them with Maracyn I and II combined. I hope this helps you and I'm really sorry you lost Fleur.

Sorry i haven't been on for a few days, but here's an update: Big Mama is still alive, and I can't see any more fuzz around her mouth. My other three girls have been QTd for two days, and they seem to be doing well, I haven't noticed anything with them. Still preventively treating them, though. However, there are now new problems that have cropped up with Big Mama... Her anal and dorsal fins have split in several places, and she has red spots around her mouth. Stormcloud also has some splitting of her dorsal fin. Neither have been fin biting, it looks like they just... ripped.

Their fins may be a bit brittle because they're struggling with an illness. That's my best guess. The red spots on Big Mama's mouth may be open sores from where the fuzz was. The salt should help to keep those spots from becoming infected but if you have any doubt, treat her with Maracyn I and II. Otherwise, keep things as they are, it seems to be working. I'm glad Big Mama is still with us. Hang in there everyone. :)

Thanks :) I'm very concerned about the fin thing though... it's gotten worse overnight. Big Mama's anal fin is now missing huge chunks, and just seems to be falling off. There is no black edging, and she's getting 100% changes every day due to the fact I had to qt her and all my girls back in their cups :( So I don't think it's fin rot. There seems to be a bit of white around the edges of her fins, however, so I might grab the Maracyn I and II, just in case. Stormcloud's dorsal has split even more overnight, but all other fins are still intact. My unnamed girl and Aurora are still perfectly fine, if irritated at being in the cups so long :) Stormcloud, unnamed, and Aurora are all eating, but Big Mama hasn't eaten since she got sick. I'm not concerned about that too much right now, cause all my girls are fatties XD So she should have energy reserves for now.

Columnaris can and usually does attack the fins. Definitely try the Maracyn I and II and keep Big Mama in 3 tsps of AQ salt, heat at 76 too. You probably want to treat anyone with symptoms with the the Maracyn I and II, otherwise columnaris can progress pretty fast. You're right, you don't need to worry about them eating right now. First, we've got to get Big Mama back on track. Good luck, I hope she hangs in there!

Okay, so I'll definitely get the Maracyn tomorrow. I have noticed some spots popping up on my neon tetras, and only on them... they're white spots, but definitely don't look like ich. none of my tetras seem bothered by them... Could this have affected my girls? None of them have any white spots, but now I'm concerned about putting my girls back in the tank with them. I've started treating my main tank for ich, just in case, but I'm not comfortable with it :/